Messages in this thread | | | Date | Mon, 1 Dec 2008 16:15:47 -0800 | Subject | Re: [PATCH 1/2] cgroups: cleanup for dummy root | From | Paul Menage <> |
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On Fri, Nov 28, 2008 at 1:03 AM, Li Zefan <lizf@cn.fujitsu.com> wrote: > > Hmmm...Sorry, this patch is wrong, when a subsystem is inactive thus in > rootnode, it may still iterate tasks in dummy top cgroup, though currently > no subsystem does so.
Right - iterating across the tasks in a cgroup for an unmounted subsystem is a completely valid thing to do. I suppose it might make sense to optimize that to just scan the tasklist and thread lists in that case, to avoid the overhead of maintaining the cg links for the unmounted subsystems, but you'd have to change the cgroup iterator first, before you stop maintaining the links. Given that I suspect the main overhead of maintaining the links is taking css_set_lock, I'm not sure how much it hurts to be keeping the links for the inactive hierarchies too and keeping the code simpler.
Paul
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